[PATCH 0/5] crash: Small bundle of fixes for Xen

[PATCH 0/5] crash: Small bundle of fixes for Xen

[Daniel Kiper]

Hi,

It looks that Xen support for crash have not been maintained
since 2009. I am trying to fix this. Here it is small
bundle of fixes:
  - xen: Always calculate max_cpus value,
  - xen: Read only crash notes for onlined CPUs,
  - x86/xen: Read variables from dynamically allocated per_cpu data,
  - xen: Get idle data from alternative source,
  - xen: Read data correctly from dynamically allocated console ring too.

Daniel

[PATCH 0/5] crash: Small bundle of fixes for Xen

[Daniel Kiper]

Hi,

It looks that Xen support for crash have not been maintained
since 2009. I am trying to fix this. Here it is small
bundle of fixes:
  - xen: Always calculate max_cpus value,
  - xen: Read only crash notes for onlined CPUs,
  - x86/xen: Read variables from dynamically allocated per_cpu data,
  - xen: Get idle data from alternative source,
  - xen: Read data correctly from dynamically allocated console ring too.

Daniel

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[PATCH 1/5] xen: Always calculate max_cpus value

[Daniel Kiper]

max_cpus is not available since 20374 changeset (Miscellaneous data
placement adjustments). It was moved to __initdata section. This section
is freed after Xen initialization. Assume that max_cpus is always
equal to XEN_HYPER_SIZE(cpumask_t) * 8.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-06-29 16:59:18.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 14:52:59.000000000 +0200
@@ -1879,11 +1879,9 @@ xen_hyper_get_cpu_info(void)
 	uint *cpu_idx;
 	int i, j, cpus;
 
-	get_symbol_data("max_cpus", sizeof(xht->max_cpus), &xht->max_cpus);
 	XEN_HYPER_STRUCT_SIZE_INIT(cpumask_t, "cpumask_t");
-	if (XEN_HYPER_SIZE(cpumask_t) * 8 > xht->max_cpus) {
-		xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
-	}
+	xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
+
 	if (xht->cpumask) {
 		free(xht->cpumask);
 	}

[PATCH 1/5] xen: Always calculate max_cpus value

[Daniel Kiper]

max_cpus is not available since 20374 changeset (Miscellaneous data
placement adjustments). It was moved to __initdata section. This section
is freed after Xen initialization. Assume that max_cpus is always
equal to XEN_HYPER_SIZE(cpumask_t) * 8.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-06-29 16:59:18.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 14:52:59.000000000 +0200
@@ -1879,11 +1879,9 @@ xen_hyper_get_cpu_info(void)
 	uint *cpu_idx;
 	int i, j, cpus;
 
-	get_symbol_data("max_cpus", sizeof(xht->max_cpus), &xht->max_cpus);
 	XEN_HYPER_STRUCT_SIZE_INIT(cpumask_t, "cpumask_t");
-	if (XEN_HYPER_SIZE(cpumask_t) * 8 > xht->max_cpus) {
-		xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
-	}
+	xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
+
 	if (xht->cpumask) {
 		free(xht->cpumask);
 	}

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[PATCH 2/5] xen: Read only crash notes for onlined CPUs

[Daniel Kiper]

Read only crash notes for onlined CPUs. Crash notes for not running
CPUs does not exist in core file. Do not try to read them.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-07-05 15:34:45.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 15:35:05.000000000 +0200
@@ -633,18 +633,18 @@ xen_hyper_dumpinfo_init(void)
 	}
 
 	/* allocate a context area */
-	size = sizeof(struct xen_hyper_dumpinfo_context) * XEN_HYPER_MAX_CPUS();
+	size = sizeof(struct xen_hyper_dumpinfo_context) * machdep->get_smp_cpus();
 	if((xhdit->context_array = malloc(size)) == NULL) {
 		error(FATAL, "cannot malloc dumpinfo table context space.\n");
 	}
 	BZERO(xhdit->context_array, size);
-	size = sizeof(struct xen_hyper_dumpinfo_context_xen_core) * XEN_HYPER_MAX_CPUS();
+	size = sizeof(struct xen_hyper_dumpinfo_context_xen_core) * machdep->get_smp_cpus();
 	if((xhdit->context_xen_core_array = malloc(size)) == NULL) {
 		error(FATAL, "cannot malloc dumpinfo table context_xen_core_array space.\n");
 	}
 	BZERO(xhdit->context_xen_core_array, size);
 	addr = symbol_value("per_cpu__crash_notes");
-	for (i = 0; i < XEN_HYPER_MAX_CPUS(); i++) {
+	for (i = 0; i < machdep->get_smp_cpus(); i++) {
 		ulong addr_notes;
 
 		addr_notes = xen_hyper_per_cpu(addr, i);

[PATCH 2/5] xen: Read only crash notes for onlined CPUs

[Daniel Kiper]

Read only crash notes for onlined CPUs. Crash notes for not running
CPUs does not exist in core file. Do not try to read them.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-07-05 15:34:45.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 15:35:05.000000000 +0200
@@ -633,18 +633,18 @@ xen_hyper_dumpinfo_init(void)
 	}
 
 	/* allocate a context area */
-	size = sizeof(struct xen_hyper_dumpinfo_context) * XEN_HYPER_MAX_CPUS();
+	size = sizeof(struct xen_hyper_dumpinfo_context) * machdep->get_smp_cpus();
 	if((xhdit->context_array = malloc(size)) == NULL) {
 		error(FATAL, "cannot malloc dumpinfo table context space.\n");
 	}
 	BZERO(xhdit->context_array, size);
-	size = sizeof(struct xen_hyper_dumpinfo_context_xen_core) * XEN_HYPER_MAX_CPUS();
+	size = sizeof(struct xen_hyper_dumpinfo_context_xen_core) * machdep->get_smp_cpus();
 	if((xhdit->context_xen_core_array = malloc(size)) == NULL) {
 		error(FATAL, "cannot malloc dumpinfo table context_xen_core_array space.\n");
 	}
 	BZERO(xhdit->context_xen_core_array, size);
 	addr = symbol_value("per_cpu__crash_notes");
-	for (i = 0; i < XEN_HYPER_MAX_CPUS(); i++) {
+	for (i = 0; i < machdep->get_smp_cpus(); i++) {
 		ulong addr_notes;
 
 		addr_notes = xen_hyper_per_cpu(addr, i);

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[PATCH 3/5] x86/xen: Read variables from dynamically allocated per_cpu data

[Daniel Kiper]

per_cpu data is dynamically allocated since 21416 changeset (x86: Dynamically
allocate percpu data area when a CPU comes online). Take into account that
and read variables from correct address.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-07-05 15:47:09.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 15:50:19.000000000 +0200
@@ -64,7 +64,6 @@ xen_hyper_init(void)
 	machdep->get_smp_cpus();
 	machdep->memory_size();
 
-#ifdef IA64
 	if (symbol_exists("__per_cpu_offset")) {
 		xht->flags |= XEN_HYPER_SMP;
 		if((xht->__per_cpu_offset = malloc(sizeof(ulong) * XEN_HYPER_MAX_CPUS())) == NULL) {
@@ -76,7 +75,6 @@ xen_hyper_init(void)
 			error(FATAL, "cannot read __per_cpu_offset.\n");
 		}
 	}
-#endif
 
 #if defined(X86) || defined(X86_64)
 	if (symbol_exists("__per_cpu_shift")) {
diff -Npru crash-6.0.8.orig/xen_hyper_defs.h crash-6.0.8/xen_hyper_defs.h
--- crash-6.0.8.orig/xen_hyper_defs.h	2012-06-29 16:59:18.000000000 +0200
+++ crash-6.0.8/xen_hyper_defs.h	2012-07-05 15:50:19.000000000 +0200
@@ -136,7 +136,13 @@ typedef uint32_t	Elf_Word;
 
 #if defined(X86) || defined(X86_64)
 #define xen_hyper_per_cpu(var, cpu)  \
-	((ulong)(var) + (((ulong)(cpu))<<xht->percpu_shift))
+	({ ulong __var_addr; \
+	   if (xht->__per_cpu_offset) \
+		__var_addr = (xht->flags & XEN_HYPER_SMP) ? \
+			((ulong)(var) + xht->__per_cpu_offset[cpu]) : (ulong)(var); \
+	   else \
+		__var_addr = (ulong)(var) + ((ulong)(cpu) << xht->percpu_shift); \
+	   __var_addr; })
 #elif defined(IA64)
 #define xen_hyper_per_cpu(var, cpu)  \
 	((xht->flags & XEN_HYPER_SMP) ? \

[PATCH 3/5] x86/xen: Read variables from dynamically allocated per_cpu data

[Daniel Kiper]

per_cpu data is dynamically allocated since 21416 changeset (x86: Dynamically
allocate percpu data area when a CPU comes online). Take into account that
and read variables from correct address.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-07-05 15:47:09.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 15:50:19.000000000 +0200
@@ -64,7 +64,6 @@ xen_hyper_init(void)
 	machdep->get_smp_cpus();
 	machdep->memory_size();
 
-#ifdef IA64
 	if (symbol_exists("__per_cpu_offset")) {
 		xht->flags |= XEN_HYPER_SMP;
 		if((xht->__per_cpu_offset = malloc(sizeof(ulong) * XEN_HYPER_MAX_CPUS())) == NULL) {
@@ -76,7 +75,6 @@ xen_hyper_init(void)
 			error(FATAL, "cannot read __per_cpu_offset.\n");
 		}
 	}
-#endif
 
 #if defined(X86) || defined(X86_64)
 	if (symbol_exists("__per_cpu_shift")) {
diff -Npru crash-6.0.8.orig/xen_hyper_defs.h crash-6.0.8/xen_hyper_defs.h
--- crash-6.0.8.orig/xen_hyper_defs.h	2012-06-29 16:59:18.000000000 +0200
+++ crash-6.0.8/xen_hyper_defs.h	2012-07-05 15:50:19.000000000 +0200
@@ -136,7 +136,13 @@ typedef uint32_t	Elf_Word;
 
 #if defined(X86) || defined(X86_64)
 #define xen_hyper_per_cpu(var, cpu)  \
-	((ulong)(var) + (((ulong)(cpu))<<xht->percpu_shift))
+	({ ulong __var_addr; \
+	   if (xht->__per_cpu_offset) \
+		__var_addr = (xht->flags & XEN_HYPER_SMP) ? \
+			((ulong)(var) + xht->__per_cpu_offset[cpu]) : (ulong)(var); \
+	   else \
+		__var_addr = (ulong)(var) + ((ulong)(cpu) << xht->percpu_shift); \
+	   __var_addr; })
 #elif defined(IA64)
 #define xen_hyper_per_cpu(var, cpu)  \
 	((xht->flags & XEN_HYPER_SMP) ? \

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[PATCH 4/5] xen: Get idle data from alternative source

[Daniel Kiper]

idle member was removed from struct schedule_data by 21422 changeset
(Fix CPU hotplug after percpu data handling changes). Get idle data
from alternative source.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-07-05 16:05:31.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 16:08:52.000000000 +0200
@@ -397,7 +397,8 @@ xen_hyper_misc_init(void)
 	XEN_HYPER_STRUCT_SIZE_INIT(schedule_data, "schedule_data");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_schedule_lock, "schedule_data", "schedule_lock");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_curr, "schedule_data", "curr");
-	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_idle, "schedule_data", "idle");
+	if (MEMBER_EXISTS("schedule_data", "idle"))
+		XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_idle, "schedule_data", "idle");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_sched_priv, "schedule_data", "sched_priv");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_s_timer, "schedule_data", "s_timer");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_tick, "schedule_data", "tick");
@@ -539,7 +540,10 @@ xen_hyper_schedule_init(void)
 		}
 		schc->cpu_id = cpuid;
 		schc->curr = ULONG(buf + XEN_HYPER_OFFSET(schedule_data_curr));
-		schc->idle = ULONG(buf + XEN_HYPER_OFFSET(schedule_data_idle));
+		if (MEMBER_EXISTS("schedule_data", "idle"))
+			schc->idle = ULONG(buf + XEN_HYPER_OFFSET(schedule_data_idle));
+		else
+			schc->idle = xht->idle_vcpu_array[cpuid];
 		schc->sched_priv =
 			ULONG(buf + XEN_HYPER_OFFSET(schedule_data_sched_priv));
 		if (XEN_HYPER_VALID_MEMBER(schedule_data_tick))

[PATCH 4/5] xen: Get idle data from alternative source

[Daniel Kiper]

idle member was removed from struct schedule_data by 21422 changeset
(Fix CPU hotplug after percpu data handling changes). Get idle data
from alternative source.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
--- crash-6.0.8.orig/xen_hyper.c	2012-07-05 16:05:31.000000000 +0200
+++ crash-6.0.8/xen_hyper.c	2012-07-05 16:08:52.000000000 +0200
@@ -397,7 +397,8 @@ xen_hyper_misc_init(void)
 	XEN_HYPER_STRUCT_SIZE_INIT(schedule_data, "schedule_data");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_schedule_lock, "schedule_data", "schedule_lock");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_curr, "schedule_data", "curr");
-	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_idle, "schedule_data", "idle");
+	if (MEMBER_EXISTS("schedule_data", "idle"))
+		XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_idle, "schedule_data", "idle");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_sched_priv, "schedule_data", "sched_priv");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_s_timer, "schedule_data", "s_timer");
 	XEN_HYPER_MEMBER_OFFSET_INIT(schedule_data_tick, "schedule_data", "tick");
@@ -539,7 +540,10 @@ xen_hyper_schedule_init(void)
 		}
 		schc->cpu_id = cpuid;
 		schc->curr = ULONG(buf + XEN_HYPER_OFFSET(schedule_data_curr));
-		schc->idle = ULONG(buf + XEN_HYPER_OFFSET(schedule_data_idle));
+		if (MEMBER_EXISTS("schedule_data", "idle"))
+			schc->idle = ULONG(buf + XEN_HYPER_OFFSET(schedule_data_idle));
+		else
+			schc->idle = xht->idle_vcpu_array[cpuid];
 		schc->sched_priv =
 			ULONG(buf + XEN_HYPER_OFFSET(schedule_data_sched_priv));
 		if (XEN_HYPER_VALID_MEMBER(schedule_data_tick))

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[PATCH 5/5] xen: Read data correctly from dynamically allocated console ring too

[Daniel Kiper]

console ring is dynamically allocated since 19543 changeset (New option
conring_size= to allow larger console ring). Take into account that
and read data correctly from it too.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper_command.c crash-6.0.8/xen_hyper_command.c
--- crash-6.0.8.orig/xen_hyper_command.c	2012-06-29 16:59:18.000000000 +0200
+++ crash-6.0.8/xen_hyper_command.c	2012-07-05 16:22:35.000000000 +0200
@@ -590,24 +590,31 @@ xen_hyper_dump_log(void)
 	ulong conring;
 	char *buf;
 	char last;
+	uint32_t conring_size;
 
-	conring = symbol_value("conring");
+	get_symbol_data("conring", sizeof(ulong), &conring);
 	get_symbol_data("conringc", sizeof(uint), &conringc);
 	get_symbol_data("conringp", sizeof(uint), &conringp);
+
+	if (symbol_exists("conring_size"))
+		get_symbol_data("conring_size", sizeof(uint32_t), &conring_size);
+	else
+		conring_size = XEN_HYPER_CONRING_SIZE;
+
 	warp = FALSE;
-	if (conringp >= XEN_HYPER_CONRING_SIZE) {
-		if ((start = conringp & (XEN_HYPER_CONRING_SIZE - 1))) {
+	if (conringp >= conring_size) {
+		if ((start = conringp & (conring_size - 1))) {
 			warp = TRUE;
 		}
 	} else {
 		start = 0;
 	}
 
-	buf = GETBUF(XEN_HYPER_CONRING_SIZE);
-	readmem(conring, KVADDR, buf, XEN_HYPER_CONRING_SIZE,
+	buf = GETBUF(conring_size);
+	readmem(conring, KVADDR, buf, conring_size,
 		"conring contents", FAULT_ON_ERROR);
 	idx = start;
-	len = XEN_HYPER_CONRING_SIZE;
+	len = conring_size;
 	last = 0;
 
 wrap_around:

[PATCH 5/5] xen: Read data correctly from dynamically allocated console ring too

[Daniel Kiper]

console ring is dynamically allocated since 19543 changeset (New option
conring_size= to allow larger console ring). Take into account that
and read data correctly from it too.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>

diff -Npru crash-6.0.8.orig/xen_hyper_command.c crash-6.0.8/xen_hyper_command.c
--- crash-6.0.8.orig/xen_hyper_command.c	2012-06-29 16:59:18.000000000 +0200
+++ crash-6.0.8/xen_hyper_command.c	2012-07-05 16:22:35.000000000 +0200
@@ -590,24 +590,31 @@ xen_hyper_dump_log(void)
 	ulong conring;
 	char *buf;
 	char last;
+	uint32_t conring_size;
 
-	conring = symbol_value("conring");
+	get_symbol_data("conring", sizeof(ulong), &conring);
 	get_symbol_data("conringc", sizeof(uint), &conringc);
 	get_symbol_data("conringp", sizeof(uint), &conringp);
+
+	if (symbol_exists("conring_size"))
+		get_symbol_data("conring_size", sizeof(uint32_t), &conring_size);
+	else
+		conring_size = XEN_HYPER_CONRING_SIZE;
+
 	warp = FALSE;
-	if (conringp >= XEN_HYPER_CONRING_SIZE) {
-		if ((start = conringp & (XEN_HYPER_CONRING_SIZE - 1))) {
+	if (conringp >= conring_size) {
+		if ((start = conringp & (conring_size - 1))) {
 			warp = TRUE;
 		}
 	} else {
 		start = 0;
 	}
 
-	buf = GETBUF(XEN_HYPER_CONRING_SIZE);
-	readmem(conring, KVADDR, buf, XEN_HYPER_CONRING_SIZE,
+	buf = GETBUF(conring_size);
+	readmem(conring, KVADDR, buf, conring_size,
 		"conring contents", FAULT_ON_ERROR);
 	idx = start;
-	len = XEN_HYPER_CONRING_SIZE;
+	len = conring_size;
 	last = 0;
 
 wrap_around:

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Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> Hi,
> 
> It looks that Xen support for crash have not been maintained
> since 2009. I am trying to fix this. Here it is small
> bundle of fixes:
>   - xen: Always calculate max_cpus value,
>   - xen: Read only crash notes for onlined CPUs,
>   - x86/xen: Read variables from dynamically allocated per_cpu data,
>   - xen: Get idle data from alternative source,
>   - xen: Read data correctly from dynamically allocated console ring
>   too.
> 
> Daniel

Daniel,

Can you absolutely confirm that these changes are all backwards-compatible?

Thanks,
  Dave

Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> Hi,
> 
> It looks that Xen support for crash have not been maintained
> since 2009. I am trying to fix this. Here it is small
> bundle of fixes:
>   - xen: Always calculate max_cpus value,
>   - xen: Read only crash notes for onlined CPUs,
>   - x86/xen: Read variables from dynamically allocated per_cpu data,
>   - xen: Get idle data from alternative source,
>   - xen: Read data correctly from dynamically allocated console ring
>   too.
> 
> Daniel

Daniel,

Can you absolutely confirm that these changes are all backwards-compatible?

Thanks,
  Dave


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Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Daniel Kiper]

On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
>
>
> ----- Original Message -----
> > Hi,
> >
> > It looks that Xen support for crash have not been maintained
> > since 2009. I am trying to fix this. Here it is small
> > bundle of fixes:
> >   - xen: Always calculate max_cpus value,
> >   - xen: Read only crash notes for onlined CPUs,
> >   - x86/xen: Read variables from dynamically allocated per_cpu data,
> >   - xen: Get idle data from alternative source,
> >   - xen: Read data correctly from dynamically allocated console ring
> >   too.
> >
> > Daniel
>
> Daniel,
>
> Can you absolutely confirm that these changes are all backwards-compatible?

I have not done tests with older versions of Xen. However,
I made all patches with backward compatibility in mind. Anyway,
If you wish I could do tests with let's say Xen Ver. 3.4
and Xen Linux Kernel Ver. 2.6.18 at least.

Daniel

Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Daniel Kiper]

On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
>
>
> ----- Original Message -----
> > Hi,
> >
> > It looks that Xen support for crash have not been maintained
> > since 2009. I am trying to fix this. Here it is small
> > bundle of fixes:
> >   - xen: Always calculate max_cpus value,
> >   - xen: Read only crash notes for onlined CPUs,
> >   - x86/xen: Read variables from dynamically allocated per_cpu data,
> >   - xen: Get idle data from alternative source,
> >   - xen: Read data correctly from dynamically allocated console ring
> >   too.
> >
> > Daniel
>
> Daniel,
>
> Can you absolutely confirm that these changes are all backwards-compatible?

I have not done tests with older versions of Xen. However,
I made all patches with backward compatibility in mind. Anyway,
If you wish I could do tests with let's say Xen Ver. 3.4
and Xen Linux Kernel Ver. 2.6.18 at least.

Daniel

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Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Konrad Rzeszutek Wilk]

On Thu, Jul 05, 2012 at 05:29:50PM +0200, Daniel Kiper wrote:
> On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> >
> >
> > ----- Original Message -----
> > > Hi,
> > >
> > > It looks that Xen support for crash have not been maintained
> > > since 2009. I am trying to fix this. Here it is small
> > > bundle of fixes:
> > >   - xen: Always calculate max_cpus value,
> > >   - xen: Read only crash notes for onlined CPUs,
> > >   - x86/xen: Read variables from dynamically allocated per_cpu data,
> > >   - xen: Get idle data from alternative source,
> > >   - xen: Read data correctly from dynamically allocated console ring
> > >   too.
> > >
> > > Daniel
> >
> > Daniel,
> >
> > Can you absolutely confirm that these changes are all backwards-compatible?
> 
> I have not done tests with older versions of Xen. However,
> I made all patches with backward compatibility in mind. Anyway,
> If you wish I could do tests with let's say Xen Ver. 3.4
> and Xen Linux Kernel Ver. 2.6.18 at least.

I think Dave is worried about it breaking with the version that is bundled
with RHEL5U8?

Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Konrad Rzeszutek Wilk]

On Thu, Jul 05, 2012 at 05:29:50PM +0200, Daniel Kiper wrote:
> On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> >
> >
> > ----- Original Message -----
> > > Hi,
> > >
> > > It looks that Xen support for crash have not been maintained
> > > since 2009. I am trying to fix this. Here it is small
> > > bundle of fixes:
> > >   - xen: Always calculate max_cpus value,
> > >   - xen: Read only crash notes for onlined CPUs,
> > >   - x86/xen: Read variables from dynamically allocated per_cpu data,
> > >   - xen: Get idle data from alternative source,
> > >   - xen: Read data correctly from dynamically allocated console ring
> > >   too.
> > >
> > > Daniel
> >
> > Daniel,
> >
> > Can you absolutely confirm that these changes are all backwards-compatible?
> 
> I have not done tests with older versions of Xen. However,
> I made all patches with backward compatibility in mind. Anyway,
> If you wish I could do tests with let's say Xen Ver. 3.4
> and Xen Linux Kernel Ver. 2.6.18 at least.

I think Dave is worried about it breaking with the version that is bundled
with RHEL5U8?

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Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> >
> >
> > ----- Original Message -----
> > > Hi,
> > >
> > > It looks that Xen support for crash have not been maintained
> > > since 2009. I am trying to fix this. Here it is small
> > > bundle of fixes:
> > >   - xen: Always calculate max_cpus value,
> > >   - xen: Read only crash notes for onlined CPUs,
> > >   - x86/xen: Read variables from dynamically allocated per_cpu
> > >   data,
> > >   - xen: Get idle data from alternative source,
> > >   - xen: Read data correctly from dynamically allocated console
> > >   ring
> > >   too.
> > >
> > > Daniel
> >
> > Daniel,
> >
> > Can you absolutely confirm that these changes are all
> > backwards-compatible?
> 
> I have not done tests with older versions of Xen. However,
> I made all patches with backward compatibility in mind. Anyway,
> If you wish I could do tests with let's say Xen Ver. 3.4
> and Xen Linux Kernel Ver. 2.6.18 at least.
> 
> Daniel

That would be helpful -- I have very few Xen hypervisor sample dumpfiles,
and if I'm not mistaken, RHEL5 only went as far as Xen 3.1-something?

Dave

> 

Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> >
> >
> > ----- Original Message -----
> > > Hi,
> > >
> > > It looks that Xen support for crash have not been maintained
> > > since 2009. I am trying to fix this. Here it is small
> > > bundle of fixes:
> > >   - xen: Always calculate max_cpus value,
> > >   - xen: Read only crash notes for onlined CPUs,
> > >   - x86/xen: Read variables from dynamically allocated per_cpu
> > >   data,
> > >   - xen: Get idle data from alternative source,
> > >   - xen: Read data correctly from dynamically allocated console
> > >   ring
> > >   too.
> > >
> > > Daniel
> >
> > Daniel,
> >
> > Can you absolutely confirm that these changes are all
> > backwards-compatible?
> 
> I have not done tests with older versions of Xen. However,
> I made all patches with backward compatibility in mind. Anyway,
> If you wish I could do tests with let's say Xen Ver. 3.4
> and Xen Linux Kernel Ver. 2.6.18 at least.
> 
> Daniel

That would be helpful -- I have very few Xen hypervisor sample dumpfiles,
and if I'm not mistaken, RHEL5 only went as far as Xen 3.1-something?

Dave

> 

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Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Daniel Kiper]

On Thu, Jul 05, 2012 at 11:39:52AM -0400, Dave Anderson wrote:
>
>
> ----- Original Message -----
> > On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> > >
> > >
> > > ----- Original Message -----
> > > > Hi,
> > > >
> > > > It looks that Xen support for crash have not been maintained
> > > > since 2009. I am trying to fix this. Here it is small
> > > > bundle of fixes:
> > > >   - xen: Always calculate max_cpus value,
> > > >   - xen: Read only crash notes for onlined CPUs,
> > > >   - x86/xen: Read variables from dynamically allocated per_cpu
> > > >   data,
> > > >   - xen: Get idle data from alternative source,
> > > >   - xen: Read data correctly from dynamically allocated console
> > > >   ring
> > > >   too.
> > > >
> > > > Daniel
> > >
> > > Daniel,
> > >
> > > Can you absolutely confirm that these changes are all
> > > backwards-compatible?
> >
> > I have not done tests with older versions of Xen. However,
> > I made all patches with backward compatibility in mind. Anyway,
> > If you wish I could do tests with let's say Xen Ver. 3.4
> > and Xen Linux Kernel Ver. 2.6.18 at least.
> >
> > Daniel
>
> That would be helpful -- I have very few Xen hypervisor sample dumpfiles,
> and if I'm not mistaken, RHEL5 only went as far as Xen 3.1-something?

No problem. I will email you back.

Daniel

Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Daniel Kiper]

On Thu, Jul 05, 2012 at 11:39:52AM -0400, Dave Anderson wrote:
>
>
> ----- Original Message -----
> > On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> > >
> > >
> > > ----- Original Message -----
> > > > Hi,
> > > >
> > > > It looks that Xen support for crash have not been maintained
> > > > since 2009. I am trying to fix this. Here it is small
> > > > bundle of fixes:
> > > >   - xen: Always calculate max_cpus value,
> > > >   - xen: Read only crash notes for onlined CPUs,
> > > >   - x86/xen: Read variables from dynamically allocated per_cpu
> > > >   data,
> > > >   - xen: Get idle data from alternative source,
> > > >   - xen: Read data correctly from dynamically allocated console
> > > >   ring
> > > >   too.
> > > >
> > > > Daniel
> > >
> > > Daniel,
> > >
> > > Can you absolutely confirm that these changes are all
> > > backwards-compatible?
> >
> > I have not done tests with older versions of Xen. However,
> > I made all patches with backward compatibility in mind. Anyway,
> > If you wish I could do tests with let's say Xen Ver. 3.4
> > and Xen Linux Kernel Ver. 2.6.18 at least.
> >
> > Daniel
>
> That would be helpful -- I have very few Xen hypervisor sample dumpfiles,
> and if I'm not mistaken, RHEL5 only went as far as Xen 3.1-something?

No problem. I will email you back.

Daniel

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Re: [PATCH 1/5] xen: Always calculate max_cpus value

[Jan Beulich]

>>> On 05.07.12 at 17:00, Daniel Kiper <daniel.kiper@oracle.com> wrote:
> max_cpus is not available since 20374 changeset (Miscellaneous data
> placement adjustments). It was moved to __initdata section. This section
> is freed after Xen initialization. Assume that max_cpus is always
> equal to XEN_HYPER_SIZE(cpumask_t) * 8.

Using nr_cpu_ids, when available, would seem a better fit. And
I donm't see why, on dumps from old hypervisors, you wouldn't
want to continue using max_cpus. Oh, wait, I see - you would
have to be able to tell whether it actually sits in .init.data, which
might not be strait forward.

Jan

> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
> 
> diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
> --- crash-6.0.8.orig/xen_hyper.c	2012-06-29 16:59:18.000000000 +0200
> +++ crash-6.0.8/xen_hyper.c	2012-07-05 14:52:59.000000000 +0200
> @@ -1879,11 +1879,9 @@ xen_hyper_get_cpu_info(void)
>  	uint *cpu_idx;
>  	int i, j, cpus;
>  
> -	get_symbol_data("max_cpus", sizeof(xht->max_cpus), &xht->max_cpus);
>  	XEN_HYPER_STRUCT_SIZE_INIT(cpumask_t, "cpumask_t");
> -	if (XEN_HYPER_SIZE(cpumask_t) * 8 > xht->max_cpus) {
> -		xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
> -	}
> +	xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
> +
>  	if (xht->cpumask) {
>  		free(xht->cpumask);
>  	}
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org 
> http://lists.xen.org/xen-devel 

Re: [Xen-devel] [PATCH 1/5] xen: Always calculate max_cpus value

[Jan Beulich]

>>> On 05.07.12 at 17:00, Daniel Kiper <daniel.kiper@oracle.com> wrote:
> max_cpus is not available since 20374 changeset (Miscellaneous data
> placement adjustments). It was moved to __initdata section. This section
> is freed after Xen initialization. Assume that max_cpus is always
> equal to XEN_HYPER_SIZE(cpumask_t) * 8.

Using nr_cpu_ids, when available, would seem a better fit. And
I donm't see why, on dumps from old hypervisors, you wouldn't
want to continue using max_cpus. Oh, wait, I see - you would
have to be able to tell whether it actually sits in .init.data, which
might not be strait forward.

Jan

> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
> 
> diff -Npru crash-6.0.8.orig/xen_hyper.c crash-6.0.8/xen_hyper.c
> --- crash-6.0.8.orig/xen_hyper.c	2012-06-29 16:59:18.000000000 +0200
> +++ crash-6.0.8/xen_hyper.c	2012-07-05 14:52:59.000000000 +0200
> @@ -1879,11 +1879,9 @@ xen_hyper_get_cpu_info(void)
>  	uint *cpu_idx;
>  	int i, j, cpus;
>  
> -	get_symbol_data("max_cpus", sizeof(xht->max_cpus), &xht->max_cpus);
>  	XEN_HYPER_STRUCT_SIZE_INIT(cpumask_t, "cpumask_t");
> -	if (XEN_HYPER_SIZE(cpumask_t) * 8 > xht->max_cpus) {
> -		xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
> -	}
> +	xht->max_cpus = XEN_HYPER_SIZE(cpumask_t) * 8;
> +
>  	if (xht->cpumask) {
>  		free(xht->cpumask);
>  	}
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org 
> http://lists.xen.org/xen-devel 




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Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> On Thu, Jul 05, 2012 at 05:29:50PM +0200, Daniel Kiper wrote:
> > On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> > >
> > >
> > > ----- Original Message -----
> > > > Hi,
> > > >
> > > > It looks that Xen support for crash have not been maintained
> > > > since 2009. I am trying to fix this. Here it is small
> > > > bundle of fixes:
> > > >   - xen: Always calculate max_cpus value,
> > > >   - xen: Read only crash notes for onlined CPUs,
> > > >   - x86/xen: Read variables from dynamically allocated per_cpu
> > > >   data,
> > > >   - xen: Get idle data from alternative source,
> > > >   - xen: Read data correctly from dynamically allocated console
> > > >   ring
> > > >   too.
> > > >
> > > > Daniel
> > >
> > > Daniel,
> > >
> > > Can you absolutely confirm that these changes are all
> > > backwards-compatible?
> > 
> > I have not done tests with older versions of Xen. However,
> > I made all patches with backward compatibility in mind. Anyway,
> > If you wish I could do tests with let's say Xen Ver. 3.4
> > and Xen Linux Kernel Ver. 2.6.18 at least.
> 
> I think Dave is worried about it breaking with the version that is bundled
> with RHEL5U8?

Correct...

Dave
 

Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> On Thu, Jul 05, 2012 at 05:29:50PM +0200, Daniel Kiper wrote:
> > On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> > >
> > >
> > > ----- Original Message -----
> > > > Hi,
> > > >
> > > > It looks that Xen support for crash have not been maintained
> > > > since 2009. I am trying to fix this. Here it is small
> > > > bundle of fixes:
> > > >   - xen: Always calculate max_cpus value,
> > > >   - xen: Read only crash notes for onlined CPUs,
> > > >   - x86/xen: Read variables from dynamically allocated per_cpu
> > > >   data,
> > > >   - xen: Get idle data from alternative source,
> > > >   - xen: Read data correctly from dynamically allocated console
> > > >   ring
> > > >   too.
> > > >
> > > > Daniel
> > >
> > > Daniel,
> > >
> > > Can you absolutely confirm that these changes are all
> > > backwards-compatible?
> > 
> > I have not done tests with older versions of Xen. However,
> > I made all patches with backward compatibility in mind. Anyway,
> > If you wish I could do tests with let's say Xen Ver. 3.4
> > and Xen Linux Kernel Ver. 2.6.18 at least.
> 
> I think Dave is worried about it breaking with the version that is bundled
> with RHEL5U8?

Correct...

Dave
 

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Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> 
> 
> ----- Original Message -----
> > On Thu, Jul 05, 2012 at 05:29:50PM +0200, Daniel Kiper wrote:
> > > On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> > > >
> > > >
> > > > ----- Original Message -----
> > > > > Hi,
> > > > >
> > > > > It looks that Xen support for crash have not been maintained
> > > > > since 2009. I am trying to fix this. Here it is small
> > > > > bundle of fixes:
> > > > >   - xen: Always calculate max_cpus value,
> > > > >   - xen: Read only crash notes for onlined CPUs,
> > > > >   - x86/xen: Read variables from dynamically allocated
> > > > >   per_cpu
> > > > >   data,
> > > > >   - xen: Get idle data from alternative source,
> > > > >   - xen: Read data correctly from dynamically allocated
> > > > >   console
> > > > >   ring
> > > > >   too.
> > > > >
> > > > > Daniel
> > > >
> > > > Daniel,
> > > >
> > > > Can you absolutely confirm that these changes are all
> > > > backwards-compatible?
> > > 
> > > I have not done tests with older versions of Xen. However,
> > > I made all patches with backward compatibility in mind. Anyway,
> > > If you wish I could do tests with let's say Xen Ver. 3.4
> > > and Xen Linux Kernel Ver. 2.6.18 at least.
> > 
> > I think Dave is worried about it breaking with the version that is bundled
> > with RHEL5U8?
> 
> Correct...
> 
> Dave
>  

And as it turns out, it does break RHEL5 xen, at least the changes
you made for the log command:

  crash> log
  log: invalid kernel virtual address: 616e69625f64616f  type: "conring contents"
  crash>

Dave

Re: [PATCH 0/5] crash: Small bundle of fixes for Xen

[Dave Anderson]

----- Original Message -----
> 
> 
> ----- Original Message -----
> > On Thu, Jul 05, 2012 at 05:29:50PM +0200, Daniel Kiper wrote:
> > > On Thu, Jul 05, 2012 at 11:15:29AM -0400, Dave Anderson wrote:
> > > >
> > > >
> > > > ----- Original Message -----
> > > > > Hi,
> > > > >
> > > > > It looks that Xen support for crash have not been maintained
> > > > > since 2009. I am trying to fix this. Here it is small
> > > > > bundle of fixes:
> > > > >   - xen: Always calculate max_cpus value,
> > > > >   - xen: Read only crash notes for onlined CPUs,
> > > > >   - x86/xen: Read variables from dynamically allocated
> > > > >   per_cpu
> > > > >   data,
> > > > >   - xen: Get idle data from alternative source,
> > > > >   - xen: Read data correctly from dynamically allocated
> > > > >   console
> > > > >   ring
> > > > >   too.
> > > > >
> > > > > Daniel
> > > >
> > > > Daniel,
> > > >
> > > > Can you absolutely confirm that these changes are all
> > > > backwards-compatible?
> > > 
> > > I have not done tests with older versions of Xen. However,
> > > I made all patches with backward compatibility in mind. Anyway,
> > > If you wish I could do tests with let's say Xen Ver. 3.4
> > > and Xen Linux Kernel Ver. 2.6.18 at least.
> > 
> > I think Dave is worried about it breaking with the version that is bundled
> > with RHEL5U8?
> 
> Correct...
> 
> Dave
>  

And as it turns out, it does break RHEL5 xen, at least the changes
you made for the log command:

  crash> log
  log: invalid kernel virtual address: 616e69625f64616f  type: "conring contents"
  crash>

Dave


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Re: [PATCH 1/5] xen: Always calculate max_cpus value

[Daniel Kiper]

On Thu, Jul 05, 2012 at 04:56:39PM +0100, Jan Beulich wrote:
> >>> On 05.07.12 at 17:00, Daniel Kiper <daniel.kiper@oracle.com> wrote:
> > max_cpus is not available since 20374 changeset (Miscellaneous data
> > placement adjustments). It was moved to __initdata section. This section
> > is freed after Xen initialization. Assume that max_cpus is always
> > equal to XEN_HYPER_SIZE(cpumask_t) * 8.
>
> Using nr_cpu_ids, when available, would seem a better fit. And

Hmmm... I could not find such animal in Xen source code.
However, maybe I missed something.

> I donm't see why, on dumps from old hypervisors, you wouldn't
> want to continue using max_cpus. Oh, wait, I see - you would
> have to be able to tell whether it actually sits in .init.data, which
> might not be strait forward.

Yep, but I will try to improve that once again.

Daniel

Re: [Xen-devel] [PATCH 1/5] xen: Always calculate max_cpus value

[Daniel Kiper]

On Thu, Jul 05, 2012 at 04:56:39PM +0100, Jan Beulich wrote:
> >>> On 05.07.12 at 17:00, Daniel Kiper <daniel.kiper@oracle.com> wrote:
> > max_cpus is not available since 20374 changeset (Miscellaneous data
> > placement adjustments). It was moved to __initdata section. This section
> > is freed after Xen initialization. Assume that max_cpus is always
> > equal to XEN_HYPER_SIZE(cpumask_t) * 8.
>
> Using nr_cpu_ids, when available, would seem a better fit. And

Hmmm... I could not find such animal in Xen source code.
However, maybe I missed something.

> I donm't see why, on dumps from old hypervisors, you wouldn't
> want to continue using max_cpus. Oh, wait, I see - you would
> have to be able to tell whether it actually sits in .init.data, which
> might not be strait forward.

Yep, but I will try to improve that once again.

Daniel

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Re: [PATCH 1/5] xen: Always calculate max_cpus value

[Andrew Cooper]

On 13/07/12 14:19, Daniel Kiper wrote:
> On Thu, Jul 05, 2012 at 04:56:39PM +0100, Jan Beulich wrote:
>>>>> On 05.07.12 at 17:00, Daniel Kiper <daniel.kiper@oracle.com> wrote:
>>> max_cpus is not available since 20374 changeset (Miscellaneous data
>>> placement adjustments). It was moved to __initdata section. This section
>>> is freed after Xen initialization. Assume that max_cpus is always
>>> equal to XEN_HYPER_SIZE(cpumask_t) * 8.
>> Using nr_cpu_ids, when available, would seem a better fit. And
> Hmmm... I could not find such animal in Xen source code.
> However, maybe I missed something.

nr_cpu_ids was introduced into xen-unstable with c/s 23982:511d5e65a302

It is not present in 4.1 or earlier.

~Andrew

>
>> I donm't see why, on dumps from old hypervisors, you wouldn't
>> want to continue using max_cpus. Oh, wait, I see - you would
>> have to be able to tell whether it actually sits in .init.data, which
>> might not be strait forward.
> Yep, but I will try to improve that once again.
>
> Daniel

-- 
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com

Re: [Xen-devel] [PATCH 1/5] xen: Always calculate max_cpus value

[Andrew Cooper]

On 13/07/12 14:19, Daniel Kiper wrote:
> On Thu, Jul 05, 2012 at 04:56:39PM +0100, Jan Beulich wrote:
>>>>> On 05.07.12 at 17:00, Daniel Kiper <daniel.kiper@oracle.com> wrote:
>>> max_cpus is not available since 20374 changeset (Miscellaneous data
>>> placement adjustments). It was moved to __initdata section. This section
>>> is freed after Xen initialization. Assume that max_cpus is always
>>> equal to XEN_HYPER_SIZE(cpumask_t) * 8.
>> Using nr_cpu_ids, when available, would seem a better fit. And
> Hmmm... I could not find such animal in Xen source code.
> However, maybe I missed something.

nr_cpu_ids was introduced into xen-unstable with c/s 23982:511d5e65a302

It is not present in 4.1 or earlier.

~Andrew

>
>> I donm't see why, on dumps from old hypervisors, you wouldn't
>> want to continue using max_cpus. Oh, wait, I see - you would
>> have to be able to tell whether it actually sits in .init.data, which
>> might not be strait forward.
> Yep, but I will try to improve that once again.
>
> Daniel

-- 
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com




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